Field
The disclosure relates generally to the field of souring and microbiologically influenced corrosion in oil and gas production and completion fluids, as well as other industrial waters. More specifically the disclosure relates to methods for introducing controlling souring and microbiologically influenced corrosion by deleterious microbes.
Background Art
Oil and gas production and completion fluids, as well as other industrial fluids, suffer corrosion, pipe necking (partial blockage) and scale buildup in pipes and pipelines. Sources of these problems include microbially influenced corrosion (MIC) corrosion, solids produced by metabolite byproducts, and bio-film blockages. Microbes may also negatively affect oil and natural gas recovery through bacterial fouling of the water needed to hydrofracture (“frac”) reservoir rock or to “water-flood,” to increase production of oil and gas. One particular type of microbe, sulfate reducing bacteria (SRB) can contaminate or “sour” the reservoir by producing hydrogen sulfide (H2S). SRBs may produce toxic and flammable H2S, which may shorten the lifetime of piping and tankage, and introduce additional safety risks from drill rig to refinery. This H2S may react with soluble iron to produce iron sulfide. Acid producing bacteria (APB) produce acids, including a variety of organic acids, which lead to additional corrosion. SRBs and APBs may have the same effects in other oil and gas completion fluids, as well as other industrial fluids.
Traditional approaches to microbial control in oilfield and industrial waters have focused on the use of chemicals that are toxic to the target organisms (biocides). Unfortunately, the biocides are toxic to other organisms and may have significant deleterious impact to the environment.